Abstract: Imaging flow cytometry merges the capabilities of modern flow cytometry with fluorescence microscopy. Flow cytometry provides single-cell resolution of complex mixtures of cells through size, expression of surface proteins, and intracellular levels of other markers. With the advent of new fluorophores, detection systems, and analysis algorithms, dozens of distinct parameters can be analyzed on cells simultaneously. Moreover, thousands of cells can be analyzed per second, providing substantial statistical power to identify even very rare populations. A limitation of traditional flow cytometry, however, lies in its inability to resolve subcellular features or morphological changes between cells aside from overall size. Thus, processes such as autophagy or NF-?B activation that operate through the cellular re-localization of proteins to autophagosomes or the nucleus, respectively, are difficult to quantify by flow cytometry. Such features can be monitored by fluorescence microscopy, but low throughput, especially for rare cell subsets, limits its utility. Moreover, most microscopy configurations have a limited number of fluorescence parameters that can be assessed simultaneously. Imaging flow cytometry addresses these limitations by merging the advantages of flow cytometry and microscopy, taking high resolution pictures as cells pass through at low pressure but great speed. Up to 11 distinct parameters can be assessed at once, allowing for a robust separation of even rare cells with distinct combinations of surface and intracellular markers, morphology, and subcellular features. No such instrument exists at the University of Arizona or within 100 miles of Tucson. Acquisition of such an instrument would transform the capabilities of the community of local scientists studying basic cell biology, immunology, and cancer.